Pressure relief poppet valves for suspension dampers

ABSTRACT

A damper with a pressure tube and an outer tube, a piston rod extending between first and second piston rod ends, and a piston mounted to the second piston rod end. The piston is disposed within the pressure tube to define rebound and compression chambers. A reservoir chamber is positioned between the pressure tube and the outer tube and an intake valve assembly, abutting one end of the pressure tube inside the outer tube, defines at least one intermediate chamber that is arranged in fluid communication with at least one externally mounted, electro-mechanical control valve. A rebound chamber pressure relief valve, in the form of a poppet positioned inside the piston and piston rod end, releases excess fluid pressure in the rebound chamber. A compression chamber pressure relief valve, in the form of a poppet positioned inside the intake valve assembly, releases excess fluid pressure in the compression chamber.

FIELD

The present disclosure generally relates to dampers used in vehicle suspension systems. More particularly, the present disclosure relates to pressure relief poppet valves in suspension dampers.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Vehicles generally include dampers that are used in conjunction with suspension systems to absorb vibrations that occur while driving the vehicle. In order to absorb the vibrations, dampers are generally connected between a body and the suspension system of the vehicle. A piston is located within the damper. The piston is connected to the vehicle body or the suspension of the vehicle through a piston rod. The damper also includes a damper body that is connected to the suspension system. As the damper is compressed or extended, the piston may limit the flow of damping fluid between rebound and compression chambers that are defined within the damper body in order to produce a damping force that counteracts the vibrations. By further restricting the flow of damping fluid between the rebound and compression chambers of the damper, greater damping forces may be generated by the damper.

Dampers typically include one or more valves that control the flow of fluid during extension and compression motions of the piston. Many current damper designs utilize externally mounted, electromechanical valves to control extension and compression damping. However, internal pressures in such systems can exceed design requirements. As a result, passive (mechanical) blow-off valves are sometimes used to prevent the buildup of excessive pressures inside the various chambers of a damper; however, these blow-off valves often add to the dead length of a damper and/or reduce damper travel and can also introduce unwanted noise. Improved blow-off valves are therefore desirable.

SUMMARY

This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

In accordance with one aspect of the present disclosure, a damper is provided. The damper includes a pressure tube that extends co-axially about a longitudinal axis and longitudinally between first and second pressure tube ends. The damper includes a piston slidably disposed within the pressure tube. The piston defines a rebound chamber and a compression chamber within the pressure tube. The rebound chamber is longitudinally positioned between the piston and the first pressure tube end and the compression chamber is longitudinally positioned between the piston and the second pressure tube end. The piston extends longitudinally between a first piston end that faces the rebound chamber and a second piston end that faces the compression chamber. A piston rod extends co-axially with the longitudinal axis between a first piston rod end and second piston rod end. The second piston rod end is fixedly coupled to the piston.

The damper further includes a rebound chamber pressure relief valve. The rebound chamber pressure relief valve includes one or more rebound chamber pressure relief passageways, which extend through the piston from the first piston end to the second piston end, and a poppet that is configured to open and close the rebound chamber pressure relief passageway(s). The rebound chamber pressure relief valve also includes a valve cavity that extends longitudinally within the second piston rod end between an open end and a closed end and a valve seat surface that is longitudinally spaced from the open end of the valve cavity. The poppet extends longitudinally between a first poppet end and a second poppet end. The first poppet end is slidably received in the valve cavity. The second poppet end includes a valve face that is positioned to move into and out of contact with the valve seat surface to open and close the rebound chamber pressure relief passageway(s). The rebound chamber pressure relief valve also includes a spring, positioned in the valve cavity, that biases the poppet towards the compression chamber.

In accordance with another aspect of the present disclosure, the rebound chamber pressure relief valve comprises a poppet where the valve face on the second poppet end includes a chamfered surface that extends annularly and is arranged at an oblique angle relative to the longitudinal axis. In addition, the valve seat surface of the rebound chamber pressure relief valve extends annularly and is arranged at an oblique angle relative to the longitudinal axis. According to this aspect of the present disclosure, the chamfered surface of the valve face has a first outer diameter and the valve seat surface has a second outer diameter that is smaller than the first outer diameter. As a result of this geometry, a portion of the chamfered surface on the valve face is exposed to fluid in the rebound chamber pressure relief passageway(s) when the poppet is in a closed position and defines a surface against which the fluid pressure in the rebound chamber acts to move the poppet to an open position when the fluid pressure in the rebound chamber exceeds a blow-off pressure threshold of the rebound chamber pressure relief valve.

In accordance with another aspect of the present disclosure, the damper also includes an outer tube disposed around the pressure tube to define a reservoir chamber between the pressure tube and the outer tube. The outer tube extends longitudinally between first and second outer tube ends. According to this aspect of the present disclosure, the damper also includes an intake valve assembly, an accumulation chamber, and a compression chamber pressure relief valve. The intake valve assembly is positioned within the outer tube and extends longitudinally between a first intake valve assembly end and a second intake valve assembly end. The intake valve assembly includes at least one intermediate chamber, which is disposed in fluid communication with the compression chamber via an intermediate passageway that extends within/through the intake valve assembly. The accumulation chamber is positioned longitudinally between the intake valve assembly and the second outer tube end.

The compression chamber pressure relief valve includes one or more compression chamber pressure relief passageways that extend through the intake valve assembly between the intermediate passageway and the accumulation chamber. The compression chamber pressure relief valve includes a valve cavity that extends longitudinally within the intake valve assembly between an open end and a closed end and a valve seat surface that is longitudinally spaced from the open end of the valve cavity. A poppet of the compression chamber pressure relief valve extends longitudinally between a first poppet end and a second poppet end. The first poppet end is slidably received in the valve cavity. The second poppet end has a valve face that is positioned to move into and out of contact with the valve seat surface to open and close the compression chamber pressure relief passageway(s). The compression chamber pressure relief valve also includes a spring, positioned in the valve cavity, that biases the poppet towards the accumulation chamber.

The compression chamber pressure relief valve may also have a chamfered surface on the valve face that is exposed to fluid in the compression chamber pressure relief passageway(s) when the poppet is in a closed position and defines a surface against which the fluid pressure in the compression chamber acts to move the poppet to an open position when the fluid pressure in the compression chamber exceeds a blow-off pressure threshold of the compression chamber pressure relief valve.

Advantageously, the way in which the rebound chamber pressure relief valve is constructed and positioned inside the piston and the second piston rod end adds rebound chamber pressure relief (i.e., blow-off) functionality to the damper over and above the flowrate capabilities of the intake valve assembly and the external control valve(s) without reducing or limiting the amount of travel permitted by the damper or increasing the overall length of the damper. Similarly, the way in which the compression chamber relief valve is constructed and positioned inside the intake valve assembly adds compression chamber pressure relief (i.e., blow-off) functionality to the damper over and above the flowrate capabilities of the intake valve assembly and the external control valve(s) without reducing or limiting the amount of travel permitted by the damper or increasing the overall length of the damper. Additionally, the geometry and the chamfered surface of the valve face on the poppets of the pressure relief valves described herein provides eddies for fluid flow entering the outlet section of the pressure relief passageway(s) when the valves are in the open position, which minimizes cavitation generated noise when the pressure relief valves open.

BRIEF DESCRIPTION OF DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure.

FIG. 1 is a side perspective view of an exemplary damper constructed in accordance with the present disclosure;

FIG. 2 is a side cross-sectional view of the exemplary damper shown in FIG. 1 taken along line 2-2;

FIG. 3 is an enlarged side cross-sectional view of the exemplary damper shown in FIG. 2 , where arrows are included illustrating the fluid flow path through an exemplary compression chamber pressure relief valve of the damper during a compression stroke;

FIG. 4 is another enlarged side cross-sectional view of the exemplary damper shown in FIG. 2 , where arrows are included illustrating the fluid flow path through an exemplary rebound chamber pressure relief valve of the damper during an extension/rebound stroke;

FIG. 5A is an enlarged side cross-sectional view of the exemplary rebound chamber pressure relief valve shown in FIG. 3 , which is illustrated in a closed position;

FIG. 5B is an enlarged side cross-sectional view of the exemplary rebound chamber pressure relief valve shown in FIG. 4 , which is illustrated in an open position;

FIG. 6A is an enlarged side cross-sectional view of the exemplary compression chamber pressure relief valve shown in FIG. 4 , which is illustrated in a closed position;

FIG. 6B is an enlarged side cross-sectional view of the exemplary compression chamber pressure relief valve shown in FIG. 3 , which is illustrated in an open position;

FIG. 7 is a bottom exploded perspective view of an exemplary intake valve assembly of the exemplary damper shown in FIG. 1 ;

FIG. 8 is a top exploded perspective view of the exemplary intake valve assembly of the exemplary damper shown in FIG. 1 ; and

FIG. 9 is an enlarged side cross-sectional view of the exemplary intake valve assembly of the exemplary damper shown in FIG. 1 .

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to same or like parts.

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

FIGS. 1-4 illustrate an exemplary damper 112 for a vehicle (not shown). The damper 112 contains a fluid, such as hydraulic fluid or oil for example and without limitation. The damper 112 includes a pressure tube 122 that extends longitudinally between a first pressure tube end 156 and a second pressure tube end 157. A piston 124 is slidably disposed within the pressure tube 122. The piston 124 defines a rebound chamber 126 and a compression chamber 128 within the pressure tube 122. Each of the rebound and compression chambers 126, 128 contain the fluid therein. The rebound chamber 126 is positioned longitudinally between the piston 124 and the first pressure tube end 156 while the compression chamber 128 is positioned longitudinally between the piston 124 and the second pressure tube end 157. The volume of the rebound and compression chambers 126, 128 varies based on the movement of the piston 124. The piston 124 has a cylindrical surface that seals against the inside of the pressure tube 122 and extends longitudinally between a first piston end 125 that faces the rebound chamber 126 and a second piston end 127 that faces the compression chamber 128.

The damper 112 includes a piston rod 134. The piston rod 134 is coaxially aligned with and defines a longitudinal axis A. The piston rod 134 extends longitudinally between a first piston rod end 135 a that is configured to be connected to a component of the suspension system or the body of the vehicle and a second piston rod end 135 b that is connected to the piston 124.

The damper 112 also includes an outer tube 136 disposed annularly around the pressure tube 122 and includes an inner cylindrical surface 129 that faces and is radially spaced from the pressure tube 122 and an outer cylindrical surface 131 opposite the inner cylindrical surface 129. In some embodiments, including the one shown, the outer tube 136 is concentrically disposed around the pressure tube 122 about the longitudinal axis A. The outer tube 136 extends longitudinally between a first outer tube end 137 and a second outer tube end 139. The piston rod 134 extends longitudinally out through the first outer tube end 137. The outer tube 136 includes a closed portion 145 at the second outer tube end 139 and a cylindrical portion 147 that extends from the first outer tube end 137 to the closed portion 145 at the second outer tube end 139. Optionally, an attachment fitting 143 is mounted to the closed portion 145 of the outer tube 136. The attachment fitting 143 may be provided in the form of a hole, loop, threaded stud, or other attachment structure and is configured to attach to a component of the suspension system or the body of the vehicle. Optionally, a spring seat 200 is mounted to and extends annularly from the outer tube 136 at a location adjacent to the first outer tube end 137. The spring seat 200 may be provided to configure the damper 112 such that it may be used in a coil-over arrangement, where the spring seat 200 supports one end of a coil spring of a vehicle suspension system (not shown).

The damper 112 includes a reservoir chamber 138 that is disposed between the pressure tube 122 and the outer tube 136. The piston rod 134 extends longitudinally through a rod guide 141, which is positioned at the first outer tube end 137. Portions of the rod guide 141 mate with the first outer tube end 137 and the first pressure tube end 156. Just inboard of the rod guide 141, the first pressure tube end 156 includes one or more openings 202 that provide fluid communication between the rebound chamber 126 and the reservoir chamber 138. Stated another way, the reservoir chamber 138 is arranged in fluid communication with the rebound chamber 126 via the openings 202 in the first pressure tube end 156.

The damper 112 further includes a cover member 148 that is attached to the outer cylindrical surface 131 of the outer tube 136. By way of example and without limitation, the cover member 148 may be welded to the outer cylindrical surface 131 of the outer tube 136. A collector chamber 152 is defined between the cover member 148 and the outer tube 136. Thus, in accordance with this arrangement, the collector chamber 152 is positioned external to (i.e., radially outward of) the outer tube 136. Optionally, a charge fitting 203 may be provided on the cover member 148 to provide a location where the collector chamber 152 can be filled or re-filled with hydraulic fluid or oil.

First and second control valves 164 a, 164 b are externally mounted to the cover member 148 on the outer tube 136. Although other types of control valves can be used, in the illustrated embodiment the first and second control valves 164 a, 164 b are electro-mechanical valves. The operation of the first and second control valves 164 a, 164 b will be explained in greater detail below, but at a high level, the first and second control valves 164 a, 164 b regulate two fluid flow paths that can transport fluid into and out of the collector chamber 152. The first control valve 164 a has a first control valve axis VA1 and the second control valve 164 b has a second control valve axis VA2. The first and second control valve axes VA1 and VA2 are parallel and longitudinally spaced apart from one another, are circumferentially aligned with one another along a control valve alignment axis AA, and are arranged perpendicular to the longitudinal axis A and the control valve alignment axis AA. In other words, both the first and second control valve axes VA1 and VA2 intersect the longitudinal axis A and the control valve alignment axis AA.

In the illustrated example, the collector chamber 152 has a limited circumferential extent that extends about the outer tube 136 in an arc 149 that is less than or equal to 180 degrees. In other words, the collector chamber 152 in the illustrated example runs longitudinally along the outer tube 136 on each side of the control valve alignment axis AA. The outer tube 136 has an overall length OL that is measured longitudinally between the first and second outer tube ends 137, 139 and the collector chamber 152 has a collector chamber length CL that is measured longitudinally between first and second collector ends 151, 153. The collector chamber length CL is shorter than the overall length OL. In other words, the collector chamber 152 is shorter than the outer tube 136 and does not run along the entire length of the outer tube 136.

With additional reference to FIGS. 7-9 , the damper 112 includes an intake valve assembly 154 that is disposed inside the outer tube 136 and extends longitudinally between a first intake valve assembly end 176 and a second intake valve assembly end 178. The intake valve assembly 154 includes an adapter body 130 at the first intake valve assembly end 176, a first intake valve body 155 a that abuts the adapter body 130, a second valve body 155 b that abuts the first intake valve body 155 a, a divider body 155 c at the second intake valve assembly end 178, and a retainer body 155 d that is positioned longitudinally between the second intake valve body 155 b and the divider body 155 c in an abutting arrangement. The retainer body 155 d includes a tubular stem 210 that extends longitudinally towards the first intake valve assembly end 176 and defines an intermediate passageway 158 a therein. The adapter body 130 is press-fit onto the second pressure tube end 157. In addition, the adapter body 130 and the first and second intake valve bodies 155 a, 155 b are slid over and supported by the tubular stem 210 of the of the retainer body 155 d and a retainer ring 211 snaps into a circumferentially extending groove in the tubular stem 210 to secure the adapter body 130 and the first and second intake valve bodies 155 a, 155 b on the tubular stem 210 of the retainer body 155 d. The first and second intake valve bodies 155 a, 155 b and the divider body 155 c abut the inner cylindrical surface 129 of the outer tube 136 to define first and second intermediate chambers 159 a, 159 b inside the outer tube 136.

The first intermediate chamber 159 a is positioned longitudinally between the first and second intake valve bodies 155 a, 155 b and the second intermediate chamber 159 b is positioned longitudinally between the second intake valve body 155 b and the divider body 155 c. An accumulation chamber 162 is positioned longitudinally between the divider body 155 c and the second outer tube end 139. Thus, the first intake valve body 155 a forms a partition between the first intermediate chamber 159 a and the reservoir chamber 138, the second intake valve body 155 b forms a partition between the first and second intermediate chambers 159 a, 159 b, and the divider body 155 c forms a partition between the second intermediate chamber 159 b and the accumulation chamber 162.

The intake valve assembly 154 also includes a first intake valve 165 a that is mounted to the first intake valve body 155 a and a second intake valve 165 b that is mounted to the second intake valve body 155 b. The intermediate passageway 158 a in the tubular stem 210 of the retainer body 155 d extends longitudinally through the intake valve assembly 154 from the first intake valve assembly end 176, through adapter body 130, through the first and second intake valve bodies 155 a, 155 b, and through the retainer body 155 d to the second intake valve assembly end 178. As such, the intermediate passageway 158 a extends longitudinally through the intake valve assembly 154 and is arranged in fluid communication with the compression chamber 128 and the second intermediate chamber 159 b.

The first intake valve 165 a controls fluid flow through the intake valve assembly 154 between the first intermediate chamber 159 a and the reservoir chamber 138 while the second intake valve 165 b controls fluid flow through the intake valve assembly 154 between the first intermediate chamber 159 a and the second intermediate chamber 159 b, which leads to the intermediate passageway 158 a and ultimately the compression chamber 128.

In accordance with the illustrated embodiment, the damper 112 includes an accumulator insert 160 that is disposed within the second outer tube end 139. The accumulator insert 160 includes an accumulator sleeve 166, a floating piston 161, and a pressurized chamber (e.g., a gas chamber) 163. The accumulator sleeve 166 is positioned inside the outer tube 136 and extends between a closed end 173 adjacent to the second outer tube end 139 and an open end 174 adjacent to the intake valve assembly 154. The floating piston 161 is preassembled inside the accumulator sleeve 166 in a sliding fit. The pressurized chamber 163 is separated from the accumulation chamber 162 by the floating piston 161. Therefore, the accumulation chamber 162 is positioned longitudinally between the intake valve assembly 154 and the floating piston 161 and the pressurized chamber 163 is positioned longitudinally between the floating piston 161 and the closed end 173. The pressurized chamber 163 contains a pressurized fluid, such as a gas, that operates to bias the floating piston 161 towards the intake valve assembly 154.

The accumulator sleeve 166 extends longitudinally between the second outer tube end 139 and the intake valve assembly 154 such that the closed end 173 of the accumulator sleeve 166 abuts (i.e., contacts) the closed portion 145 of the second outer tube end 139 and such that the open end 174 of the accumulator sleeve 166 abuts the divider body 155 c of the intake valve assembly 154. Accordingly, the intake valve assembly 154 is clamped between the open end 174 of the accumulator sleeve 166 and the second pressure tube end 157 of pressure tube 122. In accordance with this arrangement, the first and second intake valve bodies 155 a, 155 b and the divider body 155 c do not need to be mechanically attached to the outer tube 136 (such as by welding) because the intake valve assembly 154 is held in place by the accumulator sleeve 166 and the pressure tube 122.

With reference to FIGS. 2-4 , the first control valve 164 a has a first control valve inlet 170 a that is arranged in fluid communication with the reservoir chamber 138 between the inner and outer tubes 122, 136 and a first control valve outlet 172 a that is arranged in fluid communication with the collector chamber 152. A first control valve port 140 in the outer tube 136 is arranged in fluid communication with and extends between the reservoir chamber 138 and the first control valve inlet 170 a. The second control valve 164 b has a second control valve inlet 170 b that is arranged in fluid communication with the second intermediate chamber 159 b and a second control valve outlet 172 b that is arranged in fluid communication with the collector chamber 152. A second control valve port 142 in the outer tube 136 is arranged in fluid communication with and extends between the second intermediate chamber 159 b and the second control valve inlet 170 b. The first control valve 164 a therefore regulates fluid flow from the reservoir chamber 138 to the collector chamber 152 and the second control valve 164 b regulates fluid flow from the second intermediate chamber 159 b to the collector chamber 152.

One or more accumulator ports 144 in the outer tube 136 are arranged in fluid communication with and extend between the collector chamber 152 and the accumulation chamber 162, while one or more open ports 146 in the outer tube 136 are arranged in fluid communication with and extend between the collector chamber 152 and the first intermediate chamber 159 a. In other words, the accumulator chamber 162 is arranged in fluid communication with the collector chamber 152 via the accumulator port(s) 144 in the outer tube 136 and the first intermediate chamber 159 a is arranged in fluid communication with the collector chamber 152 via the open port(s) 146 in the outer tube 136. The accumulator port(s) 144 and open port(s) 146 in the outer tube 136 are provided in the form of open holes, slots, or apertures that are not open or closed by a valve. As such, fluid may freely flow between the collector chamber 152 and the accumulation chamber 162 and between the collector chamber 152 and the first intermediate chamber 159 a.

In the open position, the first control valve 164 a allows fluid communication between the reservoir chamber 138 and the collector chamber 152. More particularly, the first control valve inlet 170 a is in fluid communication with the reservoir chamber 138 and the first control valve outlet 172 a is in fluid communication with the collector chamber 152. First valve member 171 a allows selective fluid communication between the first control valve inlet 170 a and the first control valve outlet 172 a and therefore selective fluid flow between the reservoir chamber 138 and the collector chamber 152, which ultimately regulates fluid flow from the rebound chamber 126 to the compression chamber 128.

In the open position, the second control valve 164 b allows fluid communication between the second intermediate chamber 159 b and the collector chamber 152. More particularly, the second control valve inlet 170 b is in fluid communication with the second intermediate chamber 159 b and the second control valve outlet 172 b is in fluid communication with the collector chamber 152. Second valve member 171 b allows selective fluid communication between the second control valve inlet 170 b and the second control valve outlet 172 b and therefore selective fluid flow between the second intermediate chamber 159 b and the collector chamber 152, which ultimately regulates fluid flow from the compression chamber 128 to both the reservoir chamber 138 and the accumulation chamber 162.

As shown in FIG. 3 , when the piston 124 moves towards the intake valve assembly 154 during a compression stroke, the volume of the compression chamber 128 decreases. The second control valve 164 b is actuated to the open position during compression strokes of the damper 112 to regulate fluid flow from the second intermediate chamber 159 b to the collector chamber 152. Specifically, the degree of opening of the second control valve 164 b may be regulated to adjust the compression damping characteristics of the damper 112. At the same time, the first control valve 164 a is in the closed position during compression strokes of the damper 112. As a result, there is no communication of fluid directly between the reservoir chamber 138 and the collector chamber 152 during a compression stroke.

During a compression stroke, a compression flow path P1 is defined inside the damper 112, where fluid in the compression chamber 128 flows through the intermediate passageway 158 a in the first intake valve assembly 154 and into the second intermediate chamber 159 b. Fluid in the second intermediate chamber 159 b flows to the second control valve inlet 170 b and passes through the second control valve port 142 in the outer tube 136. Fluid from the second control valve inlet 170 b flows to the second control valve outlet 172 b because the second control valve 164 b is in the open position and fluid from the second control valve outlet 172 b flows into the collector chamber 152. The fluid flowing into the collector chamber 152 flows into the accumulation chamber 162 via the accumulation port(s) 144 in the outer tube 136 and into the first intermediate chamber 159 a via the open port(s) 146 in the outer tube 136. If the pressure differential between the first intermediate chamber 159 a and the reservoir chamber 138 exceeds the break pressure of the first intake valve 165 a, the first intake valve 165 a will open and fluid will flow through a first set of intake orifices 158 b in the first intake valve body 155 a and into the reservoir chamber 138. Some of the fluid in the reservoir chamber 138 then flows through the openings 202 in the first pressure tube end 156 and into the rebound chamber 126, which increases in volume during compression strokes. Also, as a greater length of the piston rod 134 moves into the rebound chamber 126 during a compression stroke, the volume of the fluid that is displaced by the piston rod 134 increases. The fluid that is displaced by the piston rod 134 (i.e., the rod volume) flows into the collector chamber 152, through the accumulator port(s) 144, and into the accumulation chamber 162, which causes the floating piston 161 to move away from the intake valve assembly 154, increasing the size of the accumulation chamber 162.

As shown in FIG. 4 , when the piston 124 moves away from the intake valve assembly 154 during an extension/rebound stroke, the volume of fluid in the compression chamber 128 increases. The first control valve 164 a is actuated to the open position during extension strokes of the damper 112 to regulate fluid flow from the reservoir chamber 138 to the collector chamber 152. Specifically, the degree of opening of the first control valve 164 a may be regulated to adjust the extension/rebound damping characteristics of the damper 112. At the same time, the second control valve 164 b is in the closed position during extension strokes of the damper 112. As a result, there is no communication of fluid directly between the second intermediate chamber 159 b and the collector chamber 152 during an extension stroke.

During an extension/rebound stroke, a rebound flow path P2 is defined inside the damper 112, where fluid in the rebound chamber 126 flows into the reservoir chamber 138 via the openings 202 in the first pressure tube end 156 and the fluid in the reservoir chamber 138 then flows to the first control valve inlet 170 a and passes through the first control valve port 140 in the outer tube 136. Fluid from the first control valve inlet 170 a flows to the first control valve outlet 172 a because the first control valve 164 a is in the open position and fluid from the first control valve outlet 172 a flows into the collector chamber 152. Fluid from the collector chamber 152 flows into the first intermediate chamber 159 a via the open port(s) 146 in the outer tube 136. When the pressure differential between the first intermediate chamber 159 a and the second intermediate chamber 159 b exceeds the break pressure of the second intake valve 165 b, the second intake valve 165 b will open and fluid in the first intermediate chamber 159 a will flow through a second set of intake orifices 158 d in the second intake valve body 155 b, through the second intermediate chamber 159 b, through a plurality of channels 204 in the retainer body 155 d, through the intermediate passageway 158 a in the first intake valve assembly 154, and into the compression chamber 128. Also, the volume that is displaced by the piston rod 134 (i.e., the rod volume) decreases during an extension/rebound stroke, so an additional flow of fluid must be supplied from the accumulation chamber 162 to compensate for the decrease in the rod volume. Thus, some of the fluid in the accumulation chamber 162 flows through the accumulator port(s) 144 and into the collector chamber 152 where it joins the extension flow path P2. The net flow of fluid out of the accumulation chamber 162 causes the floating piston 161 to move towards the intake valve assembly 154, decreasing the size of the accumulation chamber 162. Thus, the intake valve assembly 154 allows bi-directional flow of fluid to and from the compression chamber 128.

As previously explained, the first and second control valves 164 a, 164 b are externally mounted on the outer tube 136 such that the first and second control valve ports 140, 142 are circumferentially aligned with each other on the outer tube 136 along the control valve alignment axis AA. To minimize the overall height of the first and second control valves 164 a, 164 b, the cover member 148 may be externally mounted to the outer tube 136 in such a way that the cover member abuts/contacts the outer cylindrical surface 131 of the outer tube 136 along the control valve alignment axis AA. In accordance with this space saving arrangement, the collector chamber 152 runs on each side of the control valve alignment axis AA, while the accumulator port(s) 144 and the open port(s) 146 in the outer tube 136 are offset relative to the first and second control valve ports 140, 142, such that the accumulator port(s) 144 and the open port(s) 146 in the outer tube 136 are circumferentially spaced relative to the control valve alignment axis AA. In other words, the ports 140, 142, 144, and 146 in the outer tube 136 of the damper 112 are arranged such that the control valve alignment axis AA bisects the first and second control valve ports 140, 142, but does not bisect the accumulator port(s) 144 and the open port(s) 146 due to their offset arrangement, which places the accumulator port(s) 144 and the open port(s) 146 in direct fluid communication with the collector chamber 152.

With reference to FIGS. 2-4 and FIGS. 5A-5B, the piston 124 includes a rebound chamber pressure relief valve 300 to limit high internal pressures within the rebound chamber 126. The piston 124 includes one or more rebound chamber pressure relief passageways 304 that extend through the piston 124 at circumferentially spaced locations from the rebound chamber 126 to the compression chamber 128.

The rebound chamber pressure relief valve 300 is configured to permit fluid flow through the rebound chamber pressure relief passageway(s) 304 in one direction from the rebound chamber 126 to the compression chamber 128 when fluid pressure in the rebound chamber 126 exceeds a blow-off pressure threshold of the rebound chamber pressure relief valve 300. In addition to the rebound chamber pressure relief passageway(s) 304, the rebound chamber pressure relief valve 300 includes a valve cavity 308 that extends longitudinally within the second piston rod end 135 b and a poppet 310 that extends longitudinally between a first poppet end 312 and a second poppet end 314. The first poppet end 312 is slidably received in the valve cavity 308 and the second poppet end 314 includes a valve face 316. The second poppet end 314 extends out from the valve cavity 308 and the valve face 316 on the second poppet end 314 is configured to open and close the rebound chamber pressure relief passageway(s) 304 in response to longitudinal movement of the poppet 310 within the valve cavity 308. The rebound chamber pressure relief valve 300 also includes a spring 318 that is positioned in the valve cavity 308 that contacts the first poppet end 312 and biases the poppet 310 towards the compression chamber 128. More specifically, the spring 318 of the rebound chamber pressure relief valve 300 applies a biasing force to the poppet 310 in a longitudinal direction pointing away from the rebound chamber 126 that defines a blow-off pressure threshold of the rebound chamber pressure relief valve 300. Although other configurations are possible, in the illustrated example, the spring 318 is a coil-spring that extends helically within the valve cavity 308. The poppet 310 is therefore configured to slide longitudinally relative to and within the valve cavity 308 from a rebound chamber pressure relief valve closed position (shown in FIGS. 3 and 5A) to a rebound chamber pressure relief valve open position (shown in FIGS. 4 and 5B) when fluid pressure in the rebound chamber 126 exceeds the blow-off pressure threshold of the rebound chamber pressure relief valve 300. Because the valve cavity 308 is positioned inside the second piston rod end 135 b, this arrangement of the rebound chamber pressure relief valve 300 does not reduce the amount of travel permitted by the damper 112 or increase the overall length OL of the damper 112.

The rebound chamber pressure relief valve 300 also includes a valve seat component 320 that is connected to the piston 124 near the second piston end 127. Although other configurations are possible, in the illustrated example, the valve seat component 320 threads into the second piston end 127. Regardless of configuration, the valve seat component 320 of the rebound chamber pressure relief valve 300 defines a valve seat surface 322. The valve cavity 308 extends longitudinally within the second piston rod end 135 b between an open end 324 and a closed end 326. The spring 318 extends longitudinally inside the valve cavity 308 and contacts the closed end 326 of the valve cavity 308 and the first poppet end 312. The valve seat surface 322 is longitudinally spaced from the open end 324 of the valve cavity 308 and is arranged in alignment with the valve face 316 on the second poppet end 314 such that the valve face 316 is positioned to move into and out of contact with the valve seat surface 322 to open and close the rebound chamber pressure relief passageway(s) 304.

The rebound chamber pressure relief passageway(s) 304 include an inlet section 328 and an outlet section 330 that are separated by closure of the valve face 316 on the valve seat surface 322 when the poppet 310 is in the rebound chamber pressure relief valve closed position (shown in FIGS. 3 and 5A). The inlet section 328 of the rebound chamber pressure relief passageway(s) 304 is arranged in fluid communication with the rebound chamber 126 and the outlet section 330 of the rebound chamber pressure relief passageway(s) 304 is arranged in fluid communication with the compression chamber 128. Although other configurations are possible, the inlet section 328 of the rebound chamber pressure relief passageway(s) 304 in the illustrated example is formed by a number of circumferentially spaced holes in the piston 124 that open into a common inlet cavity 332 that is positioned between the valve seat component 320 and portions of the piston 124 near the second piston rod end 135 b. Together, the holes in the piston 124 and the common inlet cavity 332 form the inlet section 328 of the rebound chamber pressure relief passageway(s) 304. In the illustrated example, the outlet section 330 of the rebound chamber pressure relief passageway(s) 304 is provided in the form of a single bore that is co-axially aligned with the longitudinal axis A and extends through the valve seat component 320 to the compression chamber 128.

As best seen in FIGS. 5A and 5B, the valve face 316 on the second poppet end 314 includes a chamfered surface 334 that extends annularly on the second poppet end 314. The chamfered surface 334 is arranged at an oblique angle relative to the longitudinal axis A. The valve seat surface 322 extends annularly on the valve seat component 320 and about the outlet section 330 of the rebound chamber pressure relief passageway(s) 304. The valve seat surface 322 is also arranged at an oblique angle relative to the longitudinal axis A and is generally complimentary in shape to the chamfered surface 334 on the second poppet end 314.

The chamfered surface 334 on the valve face 316 has a first outer diameter OD1 and the valve seat surface 322 on the valve seat component 320 has a second outer diameter OD2 that is smaller than the first outer diameter OD1 such that a portion of the chamfered surface 334 on the valve face 316 is exposed to fluid in the inlet section 328 of the rebound chamber pressure relief passageway(s) 304 when the poppet 310 is in the rebound chamber pressure relief valve closed position (FIGS. 3 and 5A) and defines a surface against which the fluid pressure in the common inlet cavity 332 (and therefore the rebound chamber 126) acts to move the poppet 310 towards the rebound chamber pressure relief valve open position (FIGS. 4 and 5B) when the fluid pressure in the rebound chamber 126 exceeds the blow-off pressure threshold of the rebound chamber pressure relief valve 300.

Still referring to FIGS. 5A and 5B, the chamfered surface 334 of the valve face 316 has a first inner diameter ID1 and the valve seat surface 322 of the valve seat component 320 has a second inner diameter ID2 that equals the first inner diameter ID1 of the chamfered surface 334 on the valve face 316. In addition, the outlet section 330 of the rebound chamber pressure relief passageway(s) 304 has a third diameter D3 that is larger than the second inner diameter ID2 of the valve seat surface 322 to provide one or more eddies 338 for fluid flow entering the outlet section 330 of the rebound chamber pressure relief passageway(s) 304 when the poppet 310 is in the rebound chamber pressure relief valve open position (shown in FIGS. 4 and 5B). The eddies 338 provide an oil clearance space around the jet/primary flow of fluid through the rebound chamber pressure relief valve 300 where fluid/oil exhibits a recirculation flow/turbulent currents, which helps to minimize cavitation generated noise when the rebound chamber pressure relief valve 300 is opened.

The poppet 310 includes a through-bore 340 that extends longitudinally between the first poppet end 312 and the second poppet end 314, which permits fluid flow through the poppet 310 and pressure equalization between the valve cavity 308 in the second piston rod end 135 b and the outlet section 330 of the rebound chamber pressure relief passageway(s) 304 and therefore the compression chamber 128. As a result, the blow-off pressure threshold of the rebound chamber pressure relief valve 300 is defined by the biasing force the spring 318 applies to the poppet 310. The poppet 310 may optionally include one or more seals 342 that extend annularly about the poppet 310 and sealingly engage the valve cavity 308 without preventing sliding movement of the poppet 310 within the valve cavity 308.

The first poppet end 312 is configured to slide longitudinally within the valve cavity 308 such that the valve face 316 on the second poppet end 314 will move away from the valve seat surface 322 of the valve seat component 320 and define a rebound chamber pressure relief valve open position (FIGS. 4 and 5B) when fluid pressure in the rebound chamber 126 exceeds the blow-off pressure threshold of the rebound chamber pressure relief valve 300. In this position, the rebound chamber pressure relief valve 300 permits fluid flow B2 to pass from the rebound chamber 126, through the rebound chamber pressure relief passageway(s) 304, and out into the compression chamber 128.

With reference to FIGS. 2-4 and FIGS. 6A-6B, the damper 112 also includes a compression chamber pressure relief valve 400 to limit high internal pressures within the compression chamber 128. The intake valve assembly 154 includes one or more compression chamber pressure relief passageways 404 that extend through the divider body 155 c of the intake valve assembly 154 between the intermediate passageway 158 a and the accumulation chamber 162. The compression chamber pressure relief valve 400 is configured to permit fluid flow through the compression chamber pressure relief passageway(s) 404 in one direction from the intermediate passageway 158 a to the accumulation chamber 162 when fluid pressure in the compression chamber 128 exceeds a blow-off pressure threshold of the compression chamber pressure relief valve 400.

In addition to the compression chamber pressure relief passageway(s) 404, the compression chamber pressure relief valve 400 includes a valve housing 402 that extends longitudinally within the intermediate passageway 158 a. The valve housing 402 has a tubular shape that defines a valve cavity 408 therein with one open end 424 and one closed end 426. However, it should be appreciated that other arrangements are possible where the valve housing 402 is eliminated and one or more components of the intake valve assembly 154 form the valve cavity 408. The compression chamber pressure relief valve 400 further includes a poppet 410 that extends longitudinally between a first poppet end 412 and a second poppet end 414. The first poppet end 412 is slidably received in the valve cavity 408 and the second poppet end 414 includes a valve face 416. The second poppet end 414 extends out from the valve cavity 408 and the valve face 416 on the second poppet end 414 is configured to open and close the compression chamber pressure relief passageway(s) 404 in response to longitudinal movement of the poppet 410 within the valve cavity 408. The compression chamber pressure relief valve 400 also includes a spring 418 that is positioned in the valve cavity 408 that contacts the first poppet end 412 and biases the poppet 410 towards the accumulation chamber 162. More specifically, the spring 418 pushes the second poppet end 414 against the divider body 155 c to obstruct fluid flow through the compression chamber pressure relief passageway(s) 404 when the compression chamber pressure relief valve 400 is in a compression chamber pressure relief valve closed position (as illustrated in FIGS. 4 and 6A).

The spring 418 of the compression chamber pressure relief valve 400 extends longitudinally inside the valve cavity 408 and contacts the closed end 426 of the valve cavity 408 and the first poppet end 412. As a result, the spring 418 applies a biasing force to the poppet 410 in a longitudinal direction pointing away from the compression chamber 128 that defines a blow-off pressure threshold of the compression chamber pressure relief valve 400. Although other configurations are possible, in the illustrated example, the spring 418 is a coil-spring that extends helically within the valve cavity 408. The poppet 410 is therefore configured to slide longitudinally relative to and within the valve cavity 408 from a compression chamber pressure relief valve closed position (shown in FIGS. 4 and 6A) to a rebound chamber pressure relief valve open position (shown in FIGS. 3 and 6B) when fluid pressure in the compression chamber 128 exceeds the blow-off pressure threshold of the compression chamber pressure relief valve 400. Because the valve cavity 408 is positioned inside the intake valve assembly 154, this arrangement of the compression chamber pressure relief valve 400 does not reduce the amount of travel permitted by the damper 112 or increase the overall length OL of the damper 112.

The compression chamber pressure relief valve 400 also includes a valve seat component 420 that is connected to the divider body 155 c. Although other configurations are possible, in the illustrated example, the valve seat component 420 threads into the divider body 155 c. Regardless of configuration, the valve seat component 420 of the compression chamber pressure relief valve 400 defines a valve seat surface 422. The valve seat surface 422 is longitudinally spaced from the open end 424 of the valve cavity 408 and is arranged in alignment with the valve face 416 on the second poppet end 414 such that the valve face 416 is positioned to move into and out of contact with the valve seat surface 422 to open and close the compression chamber pressure relief passageway(s) 404.

The compression chamber pressure relief passageway(s) 404 include an inlet section 428 and an outlet section 430 that are separated by closure of the valve face 416 on the valve seat surface 422 when the poppet 410 is in the compression chamber pressure relief valve closed position (shown in FIGS. 4 and 6A). The inlet section 428 of the compression chamber pressure relief passageway(s) 404 is arranged in fluid communication with the intermediate passageway 158 a and therefore the compression chamber 128 and the outlet section 430 of the compression chamber pressure relief passageway(s) 404 is arranged in fluid communication with the accumulation chamber 162. Although other configurations are possible, the inlet section 428 of the compression chamber pressure relief passageway(s) 404 in the illustrated example is formed by a number of circumferentially spaced holes in the divider body 155 c that open into a common inlet cavity 432 that is positioned between the valve seat component 420 and portions of the divider body 155 c. Together, the holes in the divider body 155 c and the common inlet cavity 432 form the inlet section 428 of the compression chamber pressure relief passageway(s) 404. In the illustrated example, the outlet section 430 of the compression chamber pressure relief passageway(s) 404 is provided in the form of a single bore that is co-axially aligned with the longitudinal axis A and extends through the valve seat component 420 to the accumulation chamber 162.

As best seen in FIGS. 6A and 6B, the valve face 416 on the second poppet end 414 includes a chamfered surface 434 that extends annularly on the second poppet end 414. The chamfered surface 434 is arranged at an oblique angle relative to the longitudinal axis A. The valve seat surface 422 extends annularly on the valve seat component 420 and about the outlet section 430 of the compression chamber pressure relief passageway(s) 404. The valve seat surface 422 is also arranged at an oblique angle relative to the longitudinal axis A and is complementary in shape to the chamfered surface 434 on the second poppet end 414.

The chamfered surface 434 on the valve face 416 has a first outer diameter OD1 and the valve seat surface 422 on the valve seat component 420 has a second outer diameter OD2 that is smaller than the first outer diameter OD1 such that a portion of the chamfered surface 434 on the valve face 416 is exposed to fluid in the inlet section 428 of the compression chamber pressure relief passageway(s) 404 when the poppet 410 is in the compression chamber pressure relief valve closed position (FIGS. 4 and 6A) and defines a surface against which the fluid pressure in the common inlet cavity 432 (and therefore the compression chamber 128) acts to move the poppet 410 towards the compression chamber pressure relief valve open position (FIGS. 3 and 6B) when the fluid pressure in the compression chamber 128 exceeds the blow-off pressure threshold of the compression chamber pressure relief valve 400.

Still referring to FIGS. 6A and 6B, the chamfered surface 434 of the valve face 416 has a first inner diameter ID1 and the valve seat surface 422 of the valve seat component 420 has a second inner diameter ID2 that equals the first inner diameter ID1 of the chamfered surface 434 on the valve face 416. In addition, the outlet section 430 of the compression chamber pressure relief passageway(s) 404 has a third diameter D3 that is larger than the second inner diameter ID2 of the valve seat surface 422 to provide one or more eddies 438 for fluid flow entering the outlet section 430 of the compression chamber pressure relief passageway(s) 404 when the poppet 410 is in the compression chamber pressure relief valve open position (shown in FIGS. 3 and 6B). The eddies 438 provide an oil clearance space around the jet/primary flow of fluid through the compression chamber pressure relief valve 400 where fluid/oil exhibits a recirculation flow/turbulent currents, which helps to minimize cavitation generated noise when the compression chamber pressure relief valve 400 is opened.

The poppet 410 includes a through-bore 440 that extends longitudinally between the first poppet end 412 and the second poppet end 414, which permits fluid flow through the poppet 410 and pressure equalization between the valve cavity 408 and the outlet section 430 of the compression chamber pressure relief passageway(s) 404 and therefore the accumulation chamber 162. As a result, the blow-off pressure threshold of the compression chamber pressure relief valve 400 is defined by the biasing force the spring 418 applies to the poppet 410. The poppet 410 may optionally include one or more seals 442 that extend annularly about the poppet 410 and sealingly engage the valve cavity 408 without preventing sliding movement of the poppet 410 within the valve cavity 408.

The first poppet end 412 is configured to slide longitudinally within the valve cavity 408 such that the valve face 416 on the second poppet end 414 will move away from the valve seat surface 422 of the valve seat component 420 and define a compression chamber pressure relief valve open position (FIGS. 3 and 6B) when fluid pressure in the compression chamber 128 exceeds the blow-off pressure threshold of the compression chamber pressure relief valve 400. In this position, the compression chamber pressure relief valve 400 permits fluid flow B1 to pass from the compression chamber 128, through the compression chamber pressure relief passageway(s) 404, and out into the accumulation chamber 162.

With reference to FIGS. 7-9 , the first and second intake valve bodies 155 a, 155 b of the intake valve assembly 154 are configured as vented discs. The first intake valve body 155 a includes a first center bore 206 a that extends through the first intake valve body 155 a. The first set of intake orifices 158 b are arranged circumferentially around (i.e., are radially outward of) the first center bore 206 a. The second intake valve body 155 b includes a second center bore 206 b that extends through the second intake valve body 155 b. The second set of intake orifices 158 d are arranged circumferentially around (i.e., are radially outward of) the second center bore 206 b. The adapter body 130 and the retainer body 155 d each have a cylindrical hub portion that directly abuts one of the first and second intake valve bodies 155 a, 155 b and a disc-like flange portion that retains the first and second intake valves 165 a, 165 b such that both the adapter body 130 and the retainer body 155 d have shapes similar to that of a top hat. In addition, the adapter body 130 and the retainer body 155 d have third and fourth center bores 206 c, 206 d, respectively. The first center bore 206 a in the first intake valve body 155 a, the second center bore 206 b in the second intake valve body 155 b, the third center bore 206 c in the adapter body 130, and the fourth center bore 206 d in the retainer body 155 d are aligned with one another and co-axially aligned with the central longitudinal axis A of the damper 112. The tubular stem 210 of the retainer body 155 d extends through the first center bore 206 a in the first intake valve body 155 a, the second center bore 206 b in the second intake valve body 155 b, the third center bore 206 c in the adapter body 130, and the fourth center bore 206 d in the retainer body 155 d while the fourth center bore 206 d in the retainer body 155 d defines the intermediate passageway 158 a of the intake valve assembly 154. The retainer ring 211 snaps into a circumferentially extending groove in the tubular stem 210 of the retainer body 155 d at a position near the first intake valve assembly end 176 to act as a stop that prevents the adapter body 130 and the first and second intake valve bodies 155 a, 155 b from sliding longitudinally on the tubular stem 210 of the retainer body 155 d after final assembly.

Thus, the adapter body 130 and the first and second intake valve bodies 155 a, 155 b can be pre-assembled onto the tubular stem 210 of the retainer body 155 d prior to insertion into the outer tube 136 of the damper 112. Through use of the retainer ring 211, the adapter body 130 and the first and second intake valve bodies 155 a, 155 b can be pre-assembled on the tubular stem 210 of the retainer body 155 d such that there is a pre-load on the first and second spring disc stacks 167 a, 167 b without the pre-load driving the components of the pre-assembly apart. However, it should be appreciated that the retainer ring 211 could be eliminated and the tubular stem 210 of the retainer body 155 d could be hammered or otherwise manipulated to produce an outwardly flared, mechanically deformed end to hold the components of the pre-assembly together before the pre-assembly is inserted into the outer tube 136 of the damper 112. Either way, manufacturing and assembly of the damper 112 is less complicated, more efficient, and more economical because both the intake valve assembly 154 and the accumulator insert 160 can be pre-assembled prior to installation inside the outer tube 136.

The first intake valve 165 a controls fluid flow through the first set of intake orifices 158 b between the first intermediate chamber 159 a and the reservoir chamber 138. In the illustrated example, the first intake valve 165 a is a passive valve. More specifically, in the illustrated embodiment, the first intake valve 165 a includes a first spring disc stack 167 a that is retained between the adapter body 130 and the first intake valve body 155 a. In operation, the first spring disc stack 167 a opens and closes the first set of intake orifices 158 b by flexing towards and away from the first intake valve body 155 a based on a pressure differential between the first intermediate chamber 159 a and the reservoir chamber 138. As a result, the first intake valve 165 a acts as a one-way valve that permits fluid flow in only one direction from the first intermediate chamber 159 a to the reservoir chamber 138. This one-way flow through the first intake valve 165 a occurs during compression strokes as the piston 124 moves toward the intake valve assembly 154.

The second intake valve 165 b controls fluid flow through the second set of intake orifices 158 d between the first and second intermediate chambers 159 a, 159 b. In the illustrated example, the second intake valve 165 b is a passive valve. More specifically, in the illustrated embodiment, the second intake valve 165 b includes a second spring disc stack 167 b that is retained between the second intake valve body 155 b and the retainer body 155 d. In operation, the second spring disc stack 167 b opens and closes the second set of intake orifices 158 d by flexing towards and away from the second intake valve body 155 b based on a pressure differential between the first intermediate chamber 159 a and the second intermediate chamber 159 b. The second intake valve 165 b acts as a one-way valve that permits fluid flow in only one direction from the first intermediate chamber 159 a and the second intermediate chamber 159 b. This one-way flow through the second intake valve 165 b occurs during extension strokes as the piston 124 moves away from the intake valve assembly 154. The retainer body 155 d includes a plurality of teeth 208 that are arranged to abut the divider body 155 c. The plurality of teeth 208 are circumferentially spaced to define the plurality of channels 204 in the retainer body 155 d. The channels 204 in the retainer body 155 d extend radially outwardly away from the central longitudinal axis A and therefore permit fluid flow between the second intermediate chamber 159 b and the intermediate passageway 158 a.

The rebound and compression dampening rates of the damper 112 can be dynamically controlled and adjusted between soft and firm limits by applying electric current to the externally mounted, electromechanical control valves 164 a, 164 b. However, a mutual relationship/correlation exists between the soft and firm limits due to fluid flow rate limitations through the damper 112 and the control valves 164 a, 164 b, meaning that internal pressures inside the rebound and compression chambers 126, 128 can sometimes exceed design limits when the dampening rates of the damper 112 are near or at the firm/upper limit of the adjustable dampening rate range. The rebound chamber and compression chamber pressure relief valves 300, 400 described herein release excess pressure in the rebound and compression chambers 126, 128 such that the fluid pressure does not exceed design limits, improving safety, durability, and performance, without the trade-off of consuming extra space/dead length inside the damper 112 that would either reduce the available travel distance of the damper 112 or increase its overall length OL. In other words, the rebound chamber and compression chamber pressure relief valves 300, 400 described herein are particularly advantageous in that they minimize the extra dead length typically associated with internal pressure relief (i.e., blow-off) valves.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed dampers without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof. 

What is claimed is:
 1. A damper, comprising: a pressure tube extending co-axially about a longitudinal axis and longitudinally between a first pressure tube end and a second pressure tube end; a piston slidably disposed within the pressure tube defining a rebound chamber and a compression chamber, the piston extending longitudinally between a first piston end that faces the rebound chamber and a second piston end that faces the compression chamber; a piston rod extending co-axially about the longitudinal axis and longitudinally between a first piston rod end and a second piston rod end, the second piston rod end being fixedly coupled to the piston; and a rebound chamber pressure relief valve comprising at least one rebound chamber pressure relief passageway that extends through the piston from the first piston end to the second piston end, a valve cavity that extends longitudinally within the second piston rod end between an open end and a closed end, a valve seat surface that is longitudinally spaced from the open end of the valve cavity, a poppet extending longitudinally between a first poppet end that is slidably received in the valve cavity and a second poppet end that has a valve face positioned to move into and out of contact with the valve seat surface to open and close the at least one rebound chamber pressure relief passageway, and a spring positioned in the valve cavity that biases the poppet towards the compression chamber.
 2. The damper of claim 1, wherein the spring of the rebound chamber pressure relief valve applies a biasing force to the poppet that defines a blow-off pressure threshold of the rebound chamber pressure relief valve and wherein the poppet is configured to slide longitudinally from a rebound chamber pressure relief valve closed position to a rebound chamber pressure relief valve open position when fluid pressure in the rebound chamber exceeds the blow-off pressure threshold of the rebound chamber pressure relief valve.
 3. The damper of claim 2, wherein the valve face on the second poppet end includes a chamfered surface that extends annularly and is arranged at an oblique angle relative to the longitudinal axis and wherein the valve seat surface extends annularly and is also arranged at an oblique angle relative to the longitudinal axis.
 4. The damper of claim 3, wherein the chamfered surface of the valve face has a first outer diameter and the valve seat surface has a second outer diameter that is smaller than the first outer diameter such that a portion of the chamfered surface on the valve face is exposed to fluid in the at least one rebound chamber pressure relief passageway when the poppet is in the rebound chamber pressure relief valve closed position and defines a surface against which the fluid pressure in the rebound chamber acts to move the poppet towards the rebound chamber pressure relief valve open position when the fluid pressure in the rebound chamber exceeds the blow-off pressure threshold of the rebound chamber pressure relief valve.
 5. The damper of claim 4, wherein the chamfered surface of the valve face has a first inner diameter and the valve seat surface has a second inner diameter that equals the first inner diameter of the chamfered surface on the valve face.
 6. The damper of claim 5, wherein the at least one rebound chamber pressure relief passageway includes an inlet section and an outlet section that are separated by closure of the valve face on the valve seat surface when the poppet is in the rebound chamber pressure relief valve closed position, wherein the inlet section is arranged in fluid communication with the rebound chamber and the outlet section is arranged in fluid communication with the compression chamber, and wherein the outlet section of the at least one rebound chamber pressure relief passageway has a third diameter that is larger than the second inner diameter of the valve seat surface to provide an eddy for fluid flow entering the outlet section when the poppet is in the rebound chamber pressure relief valve open position and as a result minimize cavitation generated noise.
 7. The damper of claim 6, wherein the piston includes a valve seat that is received in the second piston end and that defines the outlet section of the at least one rebound chamber pressure relief passageway and the valve seat surface which extends annularly about the outlet section.
 8. The damper of claim 2, wherein the spring extends longitudinally between and contacts the closed end of the valve cavity and the first poppet end.
 9. The damper of claim 1, wherein the poppet includes a through-bore that extends longitudinally between the first poppet end and the second poppet end that permits fluid flow and pressure equalization between the valve cavity in the second piston rod end and the outlet section of the at least one rebound chamber pressure relief passageway and therefore the compression chamber.
 10. A damper, comprising: a pressure tube extending co-axially about the longitudinal axis and longitudinally between a first pressure tube end and a second pressure tube end; a piston slidably disposed within the pressure tube defining a rebound chamber and a compression chamber; an outer tube disposed around the pressure tube to define a reservoir chamber between the pressure tube and the outer tube, the outer tube extending longitudinally between a first outer tube end and a second outer tube end; an intake valve assembly positioned within the outer tube and extending longitudinally between a first intake valve assembly end and a second intake valve assembly end, the intake valve assembly including at least one intermediate chamber disposed in fluid communication with the compression chamber via an intermediate passageway extending within the intake valve assembly; an accumulation chamber positioned longitudinally between the intake valve assembly and the second outer tube end; and a compression chamber pressure relief valve comprising at least one compression chamber pressure relief passageway that extends through the intake valve assembly between the intermediate passageway and the accumulation chamber, a valve cavity that extends longitudinally within the intake valve assembly between an open end and a closed end, a valve seat surface that is longitudinally spaced from the open end of the valve cavity, a poppet extending longitudinally between a first poppet end that is slidably received in the valve cavity and a second poppet end that has a valve face positioned to move into and out of contact with the valve seat surface to open and close the at least one compression chamber pressure relief passageway, and a spring positioned in the valve cavity that biases the poppet towards the accumulation chamber.
 11. The damper of claim 10, wherein the spring of the compression chamber pressure relief valve applies a biasing force to the poppet that defines a blow-off pressure threshold of the compression chamber pressure relief valve and wherein the poppet is configured to slide longitudinally from a compression chamber pressure relief valve closed position to a compression chamber pressure relief valve open position when fluid pressure in the compression chamber exceeds the blow-off pressure threshold of the compression chamber pressure relief valve.
 12. The damper of claim 11, wherein the intermediate passageway in the intake valve assembly extends co-axially with the longitudinal axis and wherein the compression chamber pressure relief valve includes a valve housing that extends longitudinally within the intermediate passageway and defines the valve cavity therein.
 13. The damper of claim 12, wherein the valve face on the second poppet end includes a chamfered surface that extends annularly and is arranged at an oblique angle relative to the longitudinal axis and wherein the valve seat surface extends annularly and is arranged at an oblique angle relative to the longitudinal axis.
 14. The damper of claim 13, wherein the intake valve assembly includes an adapter body at the first intake valve assembly end that abuts the second pressure tube end, a divider body at the second intake valve assembly end, a retainer body adjacent to the divider body that includes a tubular stem extending longitudinally towards the first intake valve assembly end to define the intermediate passageway, and at least one intake valve body positioned longitudinally between the adapter body and the divider body, wherein the divider body and the at least one intake valve body abut an inside cylindrical surface of the outer tube, and wherein the at least one intake valve body includes an intake valve that controls fluid flow through at least one intake orifice in the at least one intake valve body.
 15. The damper of claim 14, wherein the at least one compression chamber pressure relief passageway extends through the divider body of the intake valve assembly and includes an inlet section that is arranged in fluid communication with the intermediate passageway or the at least one intermediate chamber and an outlet section that is arranged in fluid communication with the accumulation chamber and wherein the valve seat surface is located on the divider body at a position between the inlet section and the outlet section of the at least one compression chamber pressure relief passageway.
 16. The damper of claim 15, wherein the chamfered surface of the valve face has a first outer diameter and the valve seat surface has a second outer diameter that is smaller than the first outer diameter such that a portion of the chamfered surface on the valve face is exposed to fluid in the at least one compression chamber pressure relief passageway when the poppet is in the compression chamber pressure relief valve closed position and defines a surface against which the fluid pressure in the compression chamber acts to move the poppet towards the compression chamber pressure relief valve open position when the fluid pressure in the compression chamber exceeds the blow-off pressure threshold of the compression chamber pressure relief valve.
 17. The damper of claim 16, wherein the chamfered surface of the valve face has a first inner diameter and the valve seat surface has a second inner diameter that equals the first inner diameter of the chamfered surface on the valve face.
 18. The damper of claim 17, wherein the outlet section of the at least one compression chamber pressure relief passageway has a third diameter that is larger than the second inner diameter of the valve seat surface to provide an eddy for fluid flow entering the outlet section when the poppet is in the compression chamber pressure relief valve open position and as a result minimize cavitation generated noise.
 19. The damper of claim 18, wherein the poppet includes a through-bore that extends longitudinally between the first poppet end and the second poppet end that permits fluid flow and pressure equalization between the valve cavity and the outlet section of the at least one compression chamber pressure relief passageway and therefore the accumulation chamber.
 20. A damper, comprising: a pressure tube extending co-axially about a longitudinal axis and longitudinally between a first pressure tube end and a second pressure tube end; a piston slidably disposed within the pressure tube defining a rebound chamber and a compression chamber, the piston extending longitudinally between a first piston end that faces the rebound chamber and a second piston end that faces the compression chamber; a piston rod extending co-axially about the longitudinal axis and longitudinally between a first piston rod end and a second piston rod end, the second piston rod end being fixedly coupled to the piston; and a rebound chamber pressure relief valve comprising at least one rebound chamber pressure relief passageway that extends through the piston from the first piston end to the second piston end, a valve cavity extending within at least one of the second piston rod end and the piston, and a poppet extending longitudinally between a first poppet end and a second poppet end, the second poppet end including a valve face and the first poppet end being positioned inside the valve cavity such that the valve face is configured to move into and out of contact with a valve seat surface to open and close the at least one rebound chamber pressure relief passageway, wherein the valve face on the second poppet end includes a chamfered surface that extends annularly and is arranged at an oblique angle relative to the longitudinal axis and the valve seat surface extends annularly and is arranged at an oblique angle relative to the longitudinal axis, wherein the chamfered surface of the valve face has a first outer diameter and the valve seat surface has a second outer diameter that is smaller than the first outer diameter such that a portion of the chamfered surface on the valve face is exposed to fluid in the at least one rebound chamber pressure relief passageway when the poppet is in a closed position and defines a surface against which the fluid pressure in the rebound chamber acts to move the poppet to an open position when the fluid pressure in the rebound chamber exceeds a blow-off pressure threshold of the rebound chamber pressure relief valve. 